This lacks evidence.

The federal government’s most recent climate change report, released last week, warned that global warming could cause substantial damage to the American economy, human health and the environment. The report has prompted some critics to dismiss climate scientists as corrupted by money, a common but baseless attack.

“We were paid zero dollars to produce the national assessment,” Katharine Hayhoe, an author of the report, said in an interview. “In fact, there was a reverse financial motive.”

Researchers working in climate change do not receive atypically large paychecks, nor do they strike it rich from grants. The claim also ignores that internal research from oil companies affirms the scientific consensus on climate change.

For example, at Pennsylvania State University, professors in the earth and mineral sciences department made an average salary of $157,773, which was below the universitywide average of $166,731. Professors in earth and environmental sciences earned $98,567 on average at Iowa State University, compared with the average salary of $134,039.

In the 2017 fiscal year, the federal government spent about $13.2 billion in climate change funding, according to a recent Government Accountability Office report. The bulk, about $9 billion, funded clean energy technology, while science funding accounted for $2.8 billion. Climate science funding represents about 2.4 percent of the $118.3 billion in total federal research funding in the 2017 fiscal year.

When that money trickles down to researchers, it is not padding their pockets. In a video, Dr. Hayhoe explained how a $1.1 million grant she received was spent: It was divided over four years, was split with her university for facilities costs, helped pay for a graduate assistant and covered the costs of conferences, laptops and publishing in scientific journals.

What really leads to more funding and a higher salary is a scientist’s ability to produce groundbreaking research, not confirming the consensus, Michael E. Mann, a climate scientist, wrote in his book “The Madhouse Effect.”

And contrary to Mr. Santorum’s suggestion, Exxon Mobil and other fossil fuel companies do fund research. From 1977 to 2014, 83 percent of the company’s peer-reviewed studies and 80 percent of its internal communications acknowledged that climate change is real and caused by humans, according to a 2017 study that reviewed Exxon’s documents.

“No. No. I don’t believe it. And here’s the other thing — you’re going to have to have China, and Japan, and all of Asia, and all of these other countries — you know, it — it addresses our country. Right now, we’re at the cleanest we’ve ever been, and that’s very important to me. But if we’re clean but every other place on Earth on is dirty, that’s not so good.”

False. The United States is not the cleanest country.

The United States ranked 27th out of 180 countries in an environmental performance review, compiled this year by Yale and Columbia University researchers in collaboration with the World Economic Forum. Switzerland topped the list.

The environmental performance index assigns the ranking based on 10 categories, including air and water quality, biodiversity and climate and energy.

The Climate Action Tracker, which monitors countries’ pledges to reduce emissions, has rated the United States’ efforts to reduce greenhouse gas emissions as “critically insufficient.”

What Was Said

“And you have to look at the fact that this report is based on the most extreme model scenario, which contradicts long-established trends.”

— Sarah Huckabee Sanders, the White House press secretary, in a news conference on Tuesday

The Facts

False.

The national assessment considers three model cases for greenhouse gas emissions, not just the “most extreme.” They represent a range: One model assumes that global emissions will continue to increase throughout the century, another assumes that emissions will peak by midcentury then decline, and the third assumes that emissions have already peaked.

In the appendix, the report’s authors wrote that they focused on these situations because they “capture a range of plausible atmospheric concentration futures that drive climate models.” The focus on the first two cases is consistent with the projections used by the Intergovernmental Panel on Climate Change, while the third situation assumes greater emissions reductions than estimates by the panel.

The lower emissions cases would require the world to make substantial cuts to greenhouse gas emissions in the decades ahead — but even these would still lead to considerable damage, the report says.

Linda Qiu is a fact-check reporter, based in Washington. She came to The Times in 2017 from the fact-checking service PolitiFact. @ylindaqiu